Hi,
if I got it right the reason some aggregates (such as COUNT) using only index columns are "slow" on postgresql is that it uses MVCC, so it has to read the data as well as the index. It makes sense to me, but I don't understand is how other databases (such as Oracle) do it.
Can someone explain?
Thank you.
Unisciti alla community di Io fotografo e video, il nuovo corso di fotografia di Gazzetta dello sport:
http://www.flickr.com/groups/iofotografoevideo
--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
